This invention relates generally to a binocular telescope of the type used at, for examples, the theatre, sporting events, bird watching and the like, and more particularly to a binocular telescope having a hinged and collapsible bridge whereby the binocular telescope is folded to a reduced size which is easily inserted into a clothing pocket. It is desirable that binocular telescopes should occupy a minimum amount of space when not in use. Therefore, several solutions have been propounded in the prior art in which the two telescopic bodies or monoculars can slide together to facilitate storage in a pocket.
It is known in the prior art to form a bridge linking the two telescopic bodies so that the middle planes through the bridge form a "Z" with the planes passing through the telescopic bodies and the swivel axis when the instrument is in its closed or collapsed condition. In this prior art solution to the problem of binocular size, the collapsed binocular telescope is substantially thicker than any individual telescope. As a consequence this binocular telescope when collapsed can only be stored in a pocket with difficulty. Such a binocular telescope is shown in the German Pat. DT-GM No. 7536 330.
In another binocular telescope of the prior art disclosed in German Pat. DT-OS No. 2424 792, a metal bridge is provided, against which the two telescopic bodies hinge on the same side but in the opposite directions. In this instance, the thickness of the folded telescopic unit, which determines the size of pocket in which it will be accommodated, is approximately the total of the thickness of the metal bridge plus the diameter of the telescope.
In another known design of the prior art, there is provided only one bending point on the bridge, and the telescope is folded in proportion to the strength of the bridge so that when folded, the strength of the telescopic bodies themselves is not exceeded. This solution, however, constitutes only apparent progress since it makes little sense to produce the telescopic bodies stronger than is required by the stresses normally passing through them. The flattening of a telescopic body causes the corresponding wall to draw closer to the stress path, thereby producing reflected stresses unless the telescopic bodies are enlarged to correspond to the flattening, which otherwise would not be required by the stress path per se.
What is needed is a binocular telescope which, when not in use, is folded into a small configuration without inducing undesirable stress loads in the telescopic bodies.